DeviceNet Equipment Design And Implementation

DeviceNet is a CAN–based open field-bus standard which is developed by Allen-Bradley (Rockwell Automation). It is a digital multi-point network, which establishes communications between controller and IO devices. As a communication protocol with high performance, DeviceNet enjoys a leading position in industrial markets in America and Asia, and its system solutions have also achieved remarkable growth in Europe. At home, DeviceNet has also been a national standard. In order to adapt to the development of industry in our country, research and development of our own DeviceNet products is quite necessary. However, due to the complicated protocol, special protocol conversion chips such as ANYBUS-S serials produced by HMS are usually adopted to connect to DeviceNet. There are two shortcomings when adopting hard chips as solutions. One is the high cost and disadvantage in competition. The other is the lack of independent intellectual property rights and limitation in development by forign companys.In order to improve the passive situation, this paper has analysed the protocol standard of DeviceNet in detail and realize the protocol stack of DeviceNet equipments in softwares which has reduced the cost a lot and increased economic benefits comparing to solutions of hardware chips. In addition, the independent designation of the protocol is remarkably meaningful because we will never rely on the conversion chips of foreign countries and improve the critical competitiveness in the development of products.The research of DeviceNet is generally regarded as a long-term work because its protocol standard is quite complicated and large. In order to provide a convenient environment for the research on DeviceNet in the furture, we have designed a special platform based on ARM9 and abundant peripheral equipments. With various hardware resources the researcher can devote his mind on the protocol itself easily with no regard on the limitation of hardwares which has reduced the difficulty of research on DeviceNet a lot.Finally, in order to validate the protocol stack and related softwares to work well, we have designed a controller of auto door in the paper. It has been connected to DeviceNet through the conversion between DeviceNet and self-defined communication protocol of the auto door. The experiments have proved that the protocol stack of slave station of DeviceNet can operate well in industrial fields.